As a recent electronic device becomes multifunctional, smaller, and thinner, a semiconductor device including a semiconductor element onto a package substrate serving as a wiring substrate is required to have a higher density, to be smaller, and to be thinner. As a semiconductor device attaining such purposes, a semiconductor device provided by flip chip bonding is widely used, in which plural bump electrodes formed on one main surface of the semiconductor element are electrically connected to connection electrodes of the package substrate formed at positions corresponding to the bump electrodes so as to overlap each other.
A semiconductor device connected by a flip chip bonding has a heat dissipating plate serving as a heat dissipating member which dissipates heat generated from the semiconductor element to an outside. For example, Patent Literature 1 discloses a semiconductor device using flip chip bonding. This semiconductor device includes a heat dissipating plate bonded to a semiconductor element with an adhesive layer made of a porous ceramic plate impregnated with a thermosetting resin, and also bonded to a package substrate through a ring surrounding the semiconductor element.
The flip-chip bonded semiconductor device disclosed in Patent Literature 1 has both high heat dissipating characteristics and mounting reliability. However, particularly in a mobile electronic device, when a large amount of heat is generated by the semiconductor element transmitted through the heat dissipating plate and a heat-conductive material, a temperature rises over an allowable level of a housing of the electronic device since the electronic device has a small size, thus providing a problem.
In the case that a temperature of the heat dissipating plate rises, a crack may be produced in a wiring formed on the package substrate and an external electrode used for connecting a mount substrate, such as a mother board, on which the package substrate is to be mounted, a resistance value rises, and a physical fracture is generated, hence providing another problem that a desired electric connection cannot be obtained.